This application relates to a process for the preparation of aryl triazolinones. More particularly, it relates to an improved process for the preparation of aryl triazolinones by the reaction of an aryl hydrazine with a trialkyl orthoacetate, followed by cyclizing the resulting alkoxyethylidene-substituted aryl hydrazine with a cyanate salt to form the corresponding triazolinones.
This application further relates to the improved cyclization process per se of the alkoxyethylidene-substituted aryl hydrazines to form the corresponding aryl triazolinone.
The thus-produced aryl triazolinones, for example, 4,5-dihydro-3-methyl-1-phenyl-1, 2,4-triazol-5(1H)-one, are useful as intermediates in the production of known herbicides. See, for example, U.S. Pat. Nos. 4,818,275 and 5,125,958, both of which are incorporated herein by reference, wherein conversion of these triazolinone intermediates to known herbicidal products is fully described. (See, for example, cols. 4 and 5 and 6 et seq. of the former patent, as well as col. 2 et seq. of the latter patent.)